This study aimed to evaluate the growth performance, pigment content changes, essential amino acids (EAAs), fatty acids (FAs), and proximate composition of Azolla pinnata and Azolla caroliniana grown in a greenhouse. Plants were grown in nitrogen-free Hoagland's solution at 28 +/- 2 degrees C/21 +/- 2 degrees C, day/night temperature and 60-70% humidity and examined on the 3rd, 5th, 10th and 15th days. The mean percentage of plant growth and relative growth rate for A. pinnata were 119% and 0.148 gg(-1)day(-1), respectively, while for A. caroliniana these values were 94% and 0.120 gg(-1)day(-1), respectively. Compared to day 3, the amount of total chlorophyll obtained on day 15 decreased significantly (p<0.05) for A. pinnata while the total phenolic and flavonoid contents increased significantly (p<0.05) from the 3rd to the 15th day. However, the total phenolic and flavonoid contents did not differ (p>0.0.5) in A. caroliniana. The crude protein, lipid, cellulose, ash values and the amounts of EAAs were higher in A. pinnata than A. caroliniana. Palmitic acid, oleic acid, and lignoceric acid were found to be predominant in A. pinnata and A. caroliniana. From the plant growth and pigment contents, we concluded that A. pinnata grew faster than A. caroliniana and its photosynthetic efficiency was more effective.